<section id = "api_View-onceHistoryBack" data-view = "true" data-view-title = "View.onceHistoryBack(callback)">
	<header>
		<a class = "nav-back" data-view-rel = ":back"></a>
		<span>View.onceHistoryBack(callback)</span>
		<a class = "menu"></a>
	</header>
	<div class = "body">
		<div class = "api-name">View.onceHistoryBack(callback)</div>
		<div class = "api-usage">
			添加“浏览器回退”监听器。该监听器只会被触发一次。开发者可以借助该API实现类似：“用户可以通过触摸物理返回按键，以关闭打开的商品规格选择蒙层”的特性等。如：
			<div class = "code js">
showDialog();
View.onceHistoryBack(hideDialog);
			</div>
		</div>
		<div class = "api-params"><ol>
			<li>
				callback – {Function} 回调方法
			</li>
		</ol></div>
		<div class = "api-returns">{Function} – View静态对象</div>
	</div>
	<footer><div class = "btn next">下一节</div></footer>
</section>